1. Field of the Invention
The present invention relates to a process for breeding a glabrous variety of rice crop useful for rice cultivation, particularly by a mechanical harvesting and processing by applying a tissue culture technique.
2. Description of the Related Art
Tissue culture has become extensively as a rice breeding tool, and known tissue culture techniques include anther culture, immature embryo culture, seed embryo culture, young-leaf culture, and root-tip culture.
Among these, anther culture is used mainly for the production of doubled haploid lines or the induction of somaclonal variations beneficial for breeding purposes, but the efficiency of the anther culture requires an improvement if it is to be a practically used for breeding, and the information on induced somaclonal variations has not been sufficiently documented.
As mentioned above, a glabrous variety of rice crop is highly effective for the improvement of rice cultivation, in particular the efficiency of mechanical harvesting, processing, and other work. Similar varieties have been developed by crossbreeding in the United States, but these require extremely troublesome procedures and much time.
In Japan, the Hokuriku Agricultural Experiment Station of the Ministry of Agriculture, Forestry, and Fisheries has reported that an anther culture might be used to obtain glabrous germplasm lines for further use in crossbreeding (Crop Science Laboratory No. 6, Hokuriku Agricultural Experiment Station 1979, reports on Rice Breeding, 1-19). From a viewpoint of the overall breeding process, however, this also requires troublesome procedures and much time. Namely, the use of a tissue culture technique, has not enabled the obtaining of a practical glabrous variety in the U.S., Japan, and other countries.
The object of the present invention, in consideration of the above-mentioned prior art, is the practical and efficient creation of new glabrous varieties from commercial rice varieties, in a short period and without change in the properties of the original varieties.